The invention is directed to a cyclone separator apparatus for separating solids from a gas-solid containing feed. The invention is also directed to the use of such a cyclone separator in a fluid catalytic cracking process (FCC process).
A type of cyclone separator is described in U.S. Pat. No. 4,871,514. This patent publication describes a cyclone separator which is used in a fluid catalytic cracking process to separate catalyst from the gaseous hydrocarbon products. The cyclone separator has a dipleg which has at its lower end a flapper valve. Flapper valves are also referred to as trickle valves. In normal operation the valve is in a closed position and catalyst will accumulate in the dipleg until it reaches a predetermined height in the dipleg. At this predetermined height the weight of the catalyst above the flapper valve will overcome the biasing effect holding the valve closed so that the valve opens and catalyst is released from the dipleg. In normal operation this sequence of steps will continue to take place. EP-A-383523, EP-A-488607 and U.S. Pat. No. 4,446,107 are other publications describing cyclones having a dipleg and a trickle or flapper valve at the lower end of the dipleg.
A problem often encountered with these cyclones is that the dipleg is filled with catalyst while the flapper valve remains closed. When a diplex is clogged in such a fashion the cyclone will not function in an optimal manner as a solid-gas separator and the fluid catalytic cracking process will have to be shut down in order to overcome the clogging. Because FCC processes are expected to run many months and even years between planned shutdowns any unexpected shutdown will cause considerable economic damage.
The invention relates to a method for the selective catalytic oxidation of carbon monoxide (CO) comprising catalytically oxidizing carbon monoxide in H2-rich, CO2- and H2O-containing gases in the presence of a noble metal catalyst on an xcex1-Al2O3 carrier with the addition of air as oxidizing agent. It would be advantageous to provide a cyclone separator having improved reliability, i.e. a separator which does not have the clogging problems as described above.
It has now been found that when the following apparatus is used less clogging of the dipleg will occur.
A cyclone separator apparatus for separating solids from a gas-solid containing feed resulting in a gas-rich stream, the cyclone separator comprising an upright hollow circular housing fluidly connected to a dipleg having at its lower end a flapper valve, wherein the dipleg has a lower part, which lower part has a diameter which increases from the top of the lower part to the lower end of the dipleg.